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Hypertufa Planter 


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Hypertufa Planter 

Written By: Joe Szuecs 


Cement mixer (1) 
optional, but helpful. 

Flat-blade shovel (1) 

Garden hoe (1) 

Hatchet (1) 

or other scratching implement. 

Level (1) 

Plastic mixing trough (1) 

Rubber gloves (1) 

Ruler (1) 

Safety glasses (1) 

Screwdriver (1) 


Cement (60-lb) 

bag Portland cement. 

Fencing (1) 
3' wire fencing. 

Spring clamps (4) 

Peat moss (1) 

1.5 cubic feet peat moss, sieved. 

Vermiculite (1) 

1.5 cubic feet vermiculite or per lite. 

Concrete dye (12oz) 

Plastic pot (1) 

1gal plastic nursery pot (rounded). 

Fibers (1) 

handful of concrete reinforcing fibers 


Petroleum jelly (1) 

Container (1) 

1 gallon container. 

Water and garden hose (1) 

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Acrylic admixture (16oz) 

Pagel of 13 

Hypertufa Planter 

Plastic sheet (1) 
or burlap. 

1"x1"x3' stick. 

Wire cutter (1) 

• Utility knifed) 

Wooden slats (2) 

Screws (4) 


The ultimate Zen garden accessory is the stone urn. Filled only with water and a few fallen 
leaves, it defines tranquility. Unfortunately, these stone beauties cost hundreds of dollars. 

Luckily, a concrete mix called "hypertufa" was developed that has the look of stone, 
specifically the volcanic rock called tufa. In England, farmers carved watering troughs from 
this soft, porous rock. Eventually, these tufa troughs became too expensive, and hypertufa 
containers replaced them. The materials used to make our container are inexpensive, and 
the process is delightfully messy. When it comes right down to it, a hypertufa casting is just 
a fancy mud pie. 

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Hypertufa Planter 

Step 1 — Before you start. 

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Hypertufa Planter 


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• The primary ingredient for this 
project is Portland cement. At the 
building supplies mega-store, there 
are a number of bagged cement 
products to choose from. Do not 
purchase ready-mixed concrete. 
This contains gravel, sand, and, by 
the way, Portland cement. Get pure 
Portland cement. The bags will 
usually state the type, for example 
ll-V, of the material. This isn't 
really important for this project. 
Just avoid a fast-setting product. 

• Note: Portland cement 
contains some nasty 
alkaline compounds. Wear your 
mask, safety glasses, and rubber 

• Tip: use a nursery fiber pot 
for the interior mold, this 
has two advantages: it will be much 
easier to remove than the plastic 
pot; and the rough exterior of the 
fiber pot creates a perfect texture 
on the interior of the hypertufa 

• I use a custom made outer mold. It 
makes life easier, especially when 
producing more than a few. My first 
hypertufa containers employed the 
black plastic nursery pots in the 
materials list. This is cheap and 
easy. Hypertufa is easily carved 
when first pulled from the molds, 
and you can sculpt your container 
to any shape you wish. With that 

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Hypertufa Planter 

said, a really simple and hip mold 
is a plywood box. You'll still use 
the round pot for the center of the 
piece. This is a traditional 
Japanese design. Keep the width of 
the material greater than 3" at all 
points, and finish the wood with 
paint or varnish so the hypertufa 
won't stick. (For my molds, I coat 
the interior surfaces with fiberglass 
mesh and epoxy resin.) 

• There are a number of additives 
that will improve the structural 
integrity of concrete mixtures. I've 
specified two of them: acrylic 
admixture and reinforcing fibers. 
Using these will help your container 
to better withstand weather, 
especially freeze-thaw cycles. 

• Hypertufa is messy. Don't do this 
project inside your house or 
garage, on a nice lawn, or even on 
a deck. Don't wear your favorite 
jeans. Don't dump any hypertufa 
mixture down a drain; it'll set up 

• You can add concrete dye to the 
mixture. The natural mixture will 
cure to a light tan-gray color. The 
dyes you find at the home supply 
store offer a limited palette of 
colors. Tan, charcoal, brown, and 
terra cotta are typical. Tan, 
sometimes called buff, produces a 
nice warm color. Charcoal darkens 

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Hypertufa Planter 

the material, highlighting the 
vermiculite particles and resulting 
in a granite look. 

Step 2 — Make the wire frame. 

• This step is optional, but highly recommended. Hypertufa can crack. If you embed a 
simple wire frame in the container, cracking won't end in heartbreak. You may have a 
crack, but the container won't break in two. In fact, cracks increase the wabi-sabi factor. 
The frame will be completely embedded in the walls of the container, so it doesn't have to 
look that good. 

• Look at your mold. Visualize the basic size and shape the wire frame must be to fit inside 
of the walls of the container. 

• Grab your fencing and make a tube out of it, so that it fits comfortably between the inner 
pot and the outer wall. 

• Cut off excess, and wire together to fix the tube. 

• Figure out how deep the tube should extend into the container. Cut the tube to length. If 
you plan on carving the container to shape, make sure the wire frame won't extend further 
than your design. This simple tube form will work fine. You can get fancy, as I have, and 
make the wire frame wrap around the bottom of the form as well. 

• important: Make sure the wire frame fits completely inside the container walls, 
leaving about a 1"-2" margin from any surface. 

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Hypertufa Planter 

Step 3 — Assemble the mold. 

• Position the outer container, e.g., the 5 gal. nursery pot, on level ground or a sturdy 
outdoor work surface. 

• Attach the 2 wooden slats to the top of the smaller nursery pot using the screws. The slats 
help keep the interior pot centered. 

• Now, make sure that the wire frame fits properly within the mold. Make adjustments if 

• Set the wire frame and smaller pot aside for now. 

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Hypertufa Planter 

Step 4 — Assemble your materials and make the mix. 





• Measure out the Portland cement, vermiculite/perlite, and peat moss into the mixing trough 
or cement mixer. Using a 1gal dry container, measure out 3gal vermiculite, 3gal peat 
moss, and 2gal Portland cement. You should have some leftover material. In case voids 
form in the cast, you'll use this for patching. 

• Note: if you are not using a cement mixer, skip the reinforcing fiber, it is really 
difficult to integrate the fibers well with manual mixing. 

• If you're using reinforcing fiber, toss in a handful. 

• Add water to the dry materials. Start out with 1/2 gallon or so. Mix with the garden hoe or 
cement mixer. Continue adding water, bit by bit, while mixing. The mixture must be "mud 
pie" consistency. In other words, you can form it into nice moist cakes. Dense pancake 
batter is way too wet. Crumbly is too dry. 

• If you want to add dye to the mix, do this at some point after the initial water is added. 

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Hypertufa Planter 

Step 5 — Fill the mold. 

• Shovel mix into the large nursery pot. With gloves on, compact the mixture. Once 2" of 
mix is in the pot, put in the wire frame with the top of the wire at least 1" below the top of 
the mold. 

• Continue filling/compacting the mold until the inner nursery pot, when placed on the 
mixture, is level with the top of the outer pot. 

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Hypertufa Planter 

Step 6 

• With spring clamps, secure the slats attached to the inner pot to the lip of the outer pot. 
Make sure the distance between the inner pot and outer pot edges is even all around. 

• Keep filling the sides of the mold. Don't pack so tightly that the inner pot distorts, but make 
sure mix is completely distributed, or voids will occur. Watch out for sharp points on the 
wire frame. 

• Once the mold is filled, smooth out the top. Pay special attention to the areas under the 
slats, making sure the mix is well-packed. If you run short of material, just mix up some 

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Hypertufa Planter 

Step 7 — Clean up and wait, then remove from mold. 

• Rinse out the containers and rinse off your tools promptly. Do not rinse the mix down any 
drain. If you have some mix left over, you can make some hand-formed small vessels. 

• Cover the filled mold with plastic sheeting or wet burlap. Hypertufa does not harden by 
drying, but by a process of hydration. The integrity of the final product is greatly enhanced 
by a long (about 1 month) cure. 

• After 2 days, remove the inner mold. This will be a little difficult since it will be encased in 
the hypertufa. Pull off the spring clips. With a utility knife, carefully cut away the outer 

• You'll see that the surface of the container is pretty smooth. Using the hatchet or a similar 
implement, scrape the surface of the container. Think "carved stone." Gouge and scrape. 
Round off the edges as well. Scrape down the slat marks on the rim. You probably won't 
be able to scrape the inside completely, but that's fine. Just focus on the upper surface. 

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Hypertufa Planter 

Step 8 

• Once you've scraped the entire surface, rinse with the hose. 

• If you have voids, mix up the leftover dry materials with some water. Fill the voids and 
smooth down with your hand. Let the repairs sit for a few hours and carefully scrape to 

Step 9 — Finish. 

• Cover the hypertufa container with the plastic sheeting or damp burlap. Let this sit in a 
shaded area for 2 to 4 weeks. Did I forget to mention patience as an ingredient? 

• The vessel can be used as a fountain, birdbath, or planter. For a planter, you'll need to drill 
a hole in the bottom. Hypertufa is relatively soft. Just use a regular drill or auger bit. For a 
fountain, you should seal the inner surface with a waterproof sealer. 

• Hypertufa is porous. Do not place your vessel directly on wood, carpet, or any other water- 
sensitive surface. 

• Weed whackers easily shred hypertufa. If you place it in the yard, be wary. 

• In a moist, shady area of your garden the container will develop green patches and, with 
luck, moss. You can help this along with a mixture of moss, yogurt, and clay. Grind up 
these ingredients and smear them on the container. 

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Hypertufa Planter 

This project first appeared in CRAFT Volume 03 . pages 68-75. 

This document was last generated on 2012-11-02 09:43:18 AM. 

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